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RationaleIn addition to the overwhelming lung inflammation that prevails in COVID-19, hypercoagulation and thrombosis contribute to the lethality of subjects infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Platelets are chiefly implicated in thrombosis. Moreover, they can interact with viruses and are an important source of inflammatory mediators. While a lower platelet count is associated with severity and mortality, little is known about platelet function during COVID-19. ObjectiveTo evaluate the contribution of platelets to inflammation and thrombosis in COVID-19 patients. Methods and ResultsWe document the presence of SARS-CoV-2 RNA in platelets of COVID-19 patients. Exhaustive assessment of cytokines in plasma and in platelets revealed the modulation of platelet-associated cytokine levels in COVID-19, pointing to a direct contribution of platelets to the plasmatic cytokine load. Moreover, we demonstrate that platelets release their alpha- and dense-granule contents and phosphatidylserine-exposing extracellular vesicles. Functionally, platelets were hyperactivated in COVID-19 subjects, with aggregation occurring at suboptimal thrombin concentrations. Furthermore, platelets adhered more efficiently onto collagen-coated surfaces under flow conditions. ConclusionsThese data suggest that platelets could participate in the dissemination of SARS-CoV-2 and in the overwhelming thrombo-inflammation observed in COVID-19. Thus, blockade of platelet activation pathways may improve outcomes in this disease. KEY POINTSPlatelets are a source of inflammatory cytokines and degranulate in COVID-19 Platelets contain SARS-CoV-2 RNA molecules and are prone to activation in COVID-19 Subject termsInfectious diseases/Emerging infectious diseases, SARS-CoV-2, COVID-19, Hematology, Platelets
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PURPOSE: Aberrant glycosylation of the histo-blood group antigens (including the angina bullosa haemorrhagica [ABH]) is often observed during malignant transformation in most types of carcinomas. Data concerning their ethnic distributions are diverse which explains why their biological characteristics have to be studied in different populations. Our aim was to analyze the expression of the histo-blood group (specifically the ABH) antigens in breast carcinoma.METHODS: The expression of the histo-blood group (specifically the ABH) antigens was studied in 109 patients with breast carcinoma using immunohistochemistry. Statistical analysis was performed using χ² and Fisher analyses.RESULTS: The loss of expression of histo-blood group (ABH) antigens in breast carcinoma was observed in 81.13% of patients with blood group O, 37.93% with blood group A, and 96.30% with blood group B. One key finding of this study was that the loss of expression of the ABH antigen was also observed in normal tissues adjacent to the tumor. The loss of expression was associated with higher tumor grade (p < 0.05). Expression of H antigen was observed in 50% of cases with loss of expression of B antigen and was associated with human epidermal growth factor receptor 2 (HER2) overexpression (p < 0.05). The loss of H antigen in patients with blood group O was associated with estrogen receptor expression (p < 0.001). Incompatible A antigen in tumor was expressed in 20.75% of patients with blood group O.CONCLUSION: Loss of the ABH antigens correlated with the Scarff-Bloom-Richardson histologic grading. H antigen was associated with HER2 overexpression in breast cancer. However, further studies are needed to determine the role of incompatible A antigen in mammary carcinogenesis.
